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the titrant is the one with unknown conc, (70 cards)

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1
Q

if smth not given in pract, means…

A

NO NEED THIS!!
i.e. no limewater = no carbon dioxide gas

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2
Q

powder given
hydrogen/co2/o2 test?

A

Carbonate
Co2 Test

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3
Q

silvery/shiny
hydrogen/co2/o2 test?

A

hydrogen test

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4
Q

acidify
hydrogen/co2/o2 test?

A

co2 test

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5
Q

generic solution S given
hydrogen/co2/o2 test?

A

co2

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6
Q

when anything involve H2O2
must do what?

A

hydrogen peroxide
test o2

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7
Q

what to note down when filtering

A

appearance filtrate, residue

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8
Q

what to write down for pract

A
  1. hot/cold
  2. gas is pungent (ONLY smell in pract, chlorine//ammonia)
  3. colour
  4. mixture dissolve, _ solution (clarity)
  5. no visible change
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9
Q

observation when co2/o2/h2 gas released

think about their characteristics

A

colourless, odorless gas produced

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10
Q

which gas have to write efferverscence produced

A

ALL gas
even chlorine gas e.g.

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11
Q

how to determine identity of salt/carbonate

A
  1. soluble/insoluble (SPAN)
  2. what have you added alr?

1 e.g. no ppt other than blue ppt observed therefore indicate presence, G1 ions

2 (i.e. if you add sodium hydroxide -> R, cannot say R contain sodium chloride as you have added the ion into R)

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12
Q

how desc metal (s)

A

shiny GREY solid
except Cu (brown solid)

SHINY IS NOT A COLOUR

even g1 lolol coz when u cut it as shiny as iron. dark part is oxidised (rusted) part.

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13
Q

copper(II) colour

A

red-brown

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14
Q

how desc non-transition metal compound (aq)

A

colourless soln.

main determiner of colour is still compound // element

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15
Q

wat 2 look out for

A
  1. condensation
  2. test gas
  3. colour change
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16
Q

rust/corrosion of metals
similarity

A

both req water, oxygen

corrosion is an electrolytic reaction (for wet corrosion)

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17
Q

volume to what dp

A

vol = 1dp
unless burette = 2dp

2nd dp either 5/0

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18
Q

why use styrofoam/polystyrene cup in reactions?

A

reduce heat loss, surroundings

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19
Q

how to measure rate of reaction of smth that give out gas?

A
  1. measure volume of gas
  2. in fixed time interval
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20
Q

h2o2 reaction
catalyst

A

h2o2 (reversible) h2o + o2

Manganese Oxide (IV) / Copper Oxide (I)/(II)

catalyst take part in chem reaction;
but chemically unchanged

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21
Q

recommended amt of

mass
volume of liquid
conc. of soln.

making experiment

A

mass (1-5g)
vol, liquid (10-50cm^3)
conc, soln. (0.5-2mol/dm^3)

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22
Q

how u know reaction stop when involve gas released

A

when effervescence stopped

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23
Q

observation
when qn asks us to: added solns…/leave to stand

A
  • when __ added,…
  • when left to stand, soln turn from __ -> __
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24
Q

colour of sand-like colour

A

pale brown

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25
when use "dissolve"
**desc visible change** solid react w/ soln.
26
pass steam over metal expt.
https://docs.google.com/document/d/1Ep_FO9CxYSFbxmf3Zqg9mgm9NNyt2enpfMDr49gufrU/edit?tab=t.0 page 38
27
write ionic eqn of green ppt. evolved from Fe
Fe2+ (aq) + 2OH- (aq) -> Fe(OH)2 ## Footnote state symbols depends on what they give u tbh most of the time doing the test they give soln, hence Fe2+ (**aq**) OH- is regardless of ammonia or sodium hydroxide used. essentially uw show wat u see. solution (Fe 2+) add solution (2OH-) causing ppt. (Fe(OH)2))
28
volumetric analysis 2 find moles of substance
**titration!!** 1. known conc., titrant 2. unknown conc. soln. (analyte)
29
titration table titration what to take note
final reading initial reading volume of soln. used ## Footnote **TAKE NOTE** - heading w/ unit - all reading **2DP** - 2 reading within 0.2
30
white powder green powder
white: **not** a metal green: iron (II) or copper (II) carbonate
31
heating solid brown gas evolved? when use dropper method
brown gas: No2 (g), pungent, toxic gas, produce mallest possible quantity **steps** - pinch dropper then shove it just above the reacting mixture - release - transfer pinched dropper to the limewater, making sure tip of dropper touch limewater
32
add alkali and warm to ()
test nh3 (g), see if nh4+ cation present
33
**how** gases dried
**pass gas through** fused calcium chloride/quicklime (CaO)
34
ZnO colour when hot
yellow
35
reduction w/ hydrogen expt.
https://docs.google.com/document/d/1Ep_FO9CxYSFbxmf3Zqg9mgm9NNyt2enpfMDr49gufrU/edit?tab=t.0 page 39 ## Footnote lead can still be reduced by h2 (g) as heat applied sufficient
36
reduction w/ carbon setup
https://docs.google.com/document/d/1Ep_FO9CxYSFbxmf3Zqg9mgm9NNyt2enpfMDr49gufrU/edit?tab=t.0 page 40
37
loss of mass setup
https://docs.google.com/document/d/1Ep_FO9CxYSFbxmf3Zqg9mgm9NNyt2enpfMDr49gufrU/edit?tab=t.0 page 40
38
why stir mixture, beaker b4 measure highest temp reach
even distribution heat
39
thermal decomp expt. why heat multiple times
ensure ___ fully decomposes -> ___ ## Footnote heat the test tube w/ solid multiple times until constant mass obtained
40
acidify for what
provide H+ ions (**KI**) improve oxidising power, prevent brown Mno2 form, interfere (**KMno4**) eliminate all co3 2- ions, prevent form ppt. bcuz of carbonate ions present
41
why titration consistently miss end mark nvr affect value of X in C2h2o4.xH2o
x rounded to nearest whole no. mass of moles of acid higher than water
42
titration, leave some distilled water in conical flask w/ alkali, how affect vol of acid needed, end point
does not affect vol of acid no. of moles remain same ## Footnote DILUTE ONLY AFFECTS RATE OF REACTION since theres still the same number of reactant particles at the end of the day
43
h2o2 decomposition speed up when
exposed, light, high temp
44
aq KMno4 turn what colour when very diluted
pink
45
for maximum temp expt. what affects rate of **heat loss**?
increase in limiting reagent
46
for maximum temp recorded expt (exothermic) how prevent acid spray
cover cup
47
Co2 + ca(oh)2 is what reaction
form Caco3 limewater test (precipitation) neutralisation (acid base)
48
why redox titration no need indicator
coloured substance used, oxidising agent i.e. KMno4 which indicates the end point
49
sodium thiosulfate, acid and hydrogen peroxide titration when add starch?
add in soln near end, titration point where dilute iodine, give pale yellow color ## Footnote end pt blue -> colourless
50
why remove filter funnel after titration
prevent residual liquid from entering burette, inaccurate read ## Footnote source of error if there is no removal instruction.
51
y test tube need moved, rotated about flame as its being heated
- temp of test tube not change drastically from RTP -> high temp, crack - heating solid gradual, temp gradually increase, heat all solid
52
why heating continue aft melting occur
- decompsoition of some solid components occured after it melt **test gas** ## Footnote nitrate salt decomp -> brown gas carbonate salt decomp -> co2 sulfate salt decomp -> so2
53
when there is nitrate salt heating..
- solid melts first, brown gas produced - when melt, test o2
54
oxidising/reducing agent source of error (depends on what is in burette)
OA in burette: presence of reducing agent impurities RA in burette: presence of OA impurities ## Footnote inaccurate burette readings
55
iron (II) oxide source of error
exposed to air oxidise -> iron (III) oxide ensure bottle cap
56
reading off values... qns
**draw dotted line**
57
when using heat (last resort Source of Error)
heat applied may not be consistent
58
why hydrogen chloride gas not safe
corrosive, acidic
59
why acidify with nitric acid
all nitrate salts formed are soluble will not form other ppt.
60
after crystals formed...
filter excess solution then obtain crystals
61
involve collecting gas expt. how to minimise errors
remove air from conical flask, possible impurities
62
curve and rate of reaction
as time goes from () to (), rate of reaction increases, curve gradient steeper, as products formed, as time goes from () to (), rate of reaction decreases, curve gradient gentler, as reactants used up,
63
when to use acid-carbo/thermal decomp when given a carbonate?
pref acid-carbonate as some g1/g2 may be not thermally decomposable
64
when measure rate, what intervals?
rate: 20-30s intervals
65
cover with bung
stopper with delivery tube attached to gas syringe
66
when there is unreactive substance what must do?
filter mixture
67
why water added when diluting
total vol reaction mixture constant vol of (diluted substance) proportional to concentration
68
flouride or flourine ion?
flour**ide** ion flour**ine** gas.
69
what is nesting for
set up more stable reduce heat loss, surroundings
70
how to fix swirl
inconsistent swirling use magnetic stirrer
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